package main

import "fmt"

type rect struct {
	w,h int
}

func (r rect) area() int {
	return r.w*r.h
}

func (r *rect) scale(rate int) {
	r.w*=rate
	r.h*=rate
}

func main() {
	r:=rect{5,7}
	r.scale(10)
	fmt.Println(r.area())
}
